EFFECT OF SOME MUTAGENIC AGENTS ON THE VEGETATIVE GROWTH OF Pleurotus ostreatus (Jacq. ex Fr.) P.Kumm.

Abstract

The mycelium of the edible mushroom, Pleurotus ostreatus, was exposed to electromagnetic force (E.M.F) of 7 volts, ultraviolet (UV) light of 366 nm and varying concentrations of ethanol and chloroform at time intervals ranging between 5 to 15 minutes. After exposure, they were transferred onto Potato Dextrose Agar (PDA) medium and incubated at 25± 2oC for 7 days. It was observed that the mycelia exposed to E.M.F and UV light for all time intervals employed grew on the PDA medium. Also, the mycelia exposed to 30%, 50%, and 70% concentrations of ethanol and 30% concentration of chloroform grew on the PDA medium. At chloroform concentrations higher than 30%, no growth was observed. During spawning, there was no significant difference in the rate of colonization of the spawn used i.e. sterilized grains of Sorghum bicolor, for all the test subjects and the control but during colonization of the substrate i.e. fresh and sterilized sawdust of Ceiba pentandra, there were significant differences in the rate of colonization. It took between 8 to 10 days for complete colonization of the substrate by the mycelia exposed to E.M.F, UV light and the control, while as much as 14 days for the mycelium exposed to chloroform. There was fructification for all the treatments. Thus, the research has been able to show that the production of new commercial strains of the mycelium of the edible mushroom, Pleurotus ostreatus, is achievable under laboratory conditions together with the capability to produce fruiting bodies.